CVE-2026-56853
Public on 2026-08-13
Modified on 2026-08-15
Description
When a server is configured to support unencrypted HTTP/2, it reads a few bytes from each new connection to see if they contain the HTTP/2 client preface. ReadHeaderTimeout is unexpectedly not being applied when doing this.
CVSS v3 Base Score
See breakdown
Affected Packages
| Platform | Package | Release Date | Advisory | Status |
|---|---|---|---|---|
| Amazon Linux 2 - Core | golang | 2026-08-31 | ALAS2-2026-3893 | Fixed |
| Amazon Linux 2 - Golang1.11 Extra | golang | No Fix Planned | ||
| Amazon Linux 2 - Golang1.19 Extra | golang | No Fix Planned | ||
| Amazon Linux 2 - Golang1.9 Extra | golang | No Fix Planned | ||
| Amazon Linux 2023 | golang | 2026-08-31 | ALAS2023-2026-2114 | Fixed |
| Amazon Linux 2027 Preview | golang | Pending Fix |
CVSS Scores
| Score Type | Score | Vector | |
|---|---|---|---|
| Amazon Linux | CVSSv3 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |